This invention relates to an improved invalid walker, and more particularly, to an improved invalid walker specially adapted for continuous positive operator assistance and security in ascending and descending flights of stairs.
Various walker assistance devices are commercially available for those physically handicapped persons having muscle weakness and/or lack of full muscle control which seriously affect normal walking motions and bodily balance. Such physically handicapped persons face a number of problems associated with the following normal walking and closely related activities.
1. Acquiring gait, balance and muscular control in walking.
2. Changing from walking over a level surface to ascending steps.
3. Changing from walking over a level surface to descending steps.
4. Changing from ascending stairs to a level surface.
5. Chaning from descending stairs to a level surface.
6. Traversing stairs upwardly and downwardly.
7. Resting.
Walking as described means ambulation over a planar horizontal surface, i.e., a level surface as well as traversing plural upwardly or downwardly directed steps. Each of the above activities requires a significantly different grip, balance point, center of gravity, and angle of attack.
In general, prior walker devices include a high strength, but light weight, floor supporting cage-like frame which partly surrounds and is carried by the invalid or user person. For each one or more steps the user takes, the walker is lifted from the floor and repositioned on the walking surface a short distance in the direction the user is moving and in advance of taking additional steps. Such walkers have also been modified for improved use in ascending and descending steps and stairs. U.S. Pat. No. 3,800,815 - Birk 3/2/74 is an example of such a walker. For use in ascending and descending stairs the Birk walker, which utilizes four leg supports, one at each corner of an upstanding open-sided rectangular framework, includes a lengthening adjustment for a front pair or rear pair of legs. As a result, the front legs may be supported by one of a series of steps, while the rear legs may be supported by an adjacent step at a different level, and the walker frame structure remains vertical on the stairs for better balance of the using person. The fact that the walker remains in a vertical position represents a problem for some users. When the walker is placed on a further upper and adjacent step, the user may inadvertently reach or need to reach, forwardly and upwardly and use the walker for balance and possibly for some combined downwardly and inwardly pulling effort. When the walker resides on steps of different elevations an inadvertent pull may be a dangerously unbalancing occurance in spite of the fact that the walker may be firmly vertically balanced by the adjustable legs. Such an adjustment which merely maintains the original distance between the front and rear legs does not increase the force necessary to topple the walker. Furthermore, when such a walker is placed on an adjacent higher step, the walker cage arms are significantly elevated with respect to a person on a lower step and in an awkward position for safe and effective support of the user. These and other typical disadvantages are found in other prior art walkers. Further examples of prior art walkers similar to the above noted Birk walker are disclosed and described in U.S. Pats. No 3,455,313 - King 7/15/69, 4,411,283 - Lucarelli 10/25/83 and 3,176,700 - Drury, Jr. 4/6/65.
The present invention not only provides a much improved walker structure specifically directed to the above noted problems as well as other disadvantages, but also recognizes that a physically handicapped person ordinarily needs continuity and certainty of balance and security in a walking assistance device.